Re: Gnat Ada on OpenVMS is back

[Simon Clubley <clubley@remove_me.eisner.decus.org-Earth.UFP>]

On 2017-03-03, gérard Calliet <gerard.calliet@pia-sofer.fr> wrote:
> We have built gcc a 4.7. Because, afterwards, gcc needs some c++ 
> features we did not find on itanium OpenVMS 8.4.1-h1 (from VSI, 18months 
> ago).
>

The approach I took was somewhat different as I didn't have a working
Ada compiler on VMS to be able to compile the gcc Ada frontend with.

In some discussions with Adacore several years ago, it appeared that
they were building a cross compiler on Linux and then using that
cross compiler to built a native VMS compiler on Linux, but the
difference if that they were doing this with their own version of
the gcc/binutils toolchain.

Adacore have been pushing various pieces into the FSF toolchain from
their own toolchain which is why I tried to duplicate this approach
with the FSF toolchain.

I don't know if this is the approach you took or if you relied on
having an existing GNAT Pro compiler for VMS Alpha available to be
able to build the FSF sources for an IA64 target.

Building on Linux has the downside that you need the FSF toolchain to be
sufficiently complete for you to be able to build the cross compiler.

When you say missing C++ features on VMS, are you talking about the
run-time environment or do you mean the HP C++ compiler ? If it's the
latter then I don't understand why you simply couldn't use the C++
support in gcc (unless Adacore have disabled it for their GNAT Pro
compiler for VMS Alpha).

> We had some troubles with DEC C headers, a issue with prefixes on symbols.
>

I hit the same problem back when I tried to build a cross compiler
for VMS Alpha with gcc 4.7 as well.

> The build was for a big port operation, which is just ending. Now I want 
> to take time to generalize the offer, hoping feedback of the community. 
> Please connect to our "vms ada alliance", and we could go on on gcc, for 
> the moment on Itanium. (You can perhaps find some "for hobbyist" 
> platform with itanium,  and anyway every discussion is worth it).
>

My interest in VMS is not as strong as it once was and as I don't
have an IA64 box, it's not something I can try out.

Simon.

-- 
Simon Clubley, clubley@remove_me.eisner.decus.org-Earth.UFP
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